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NSBRI, Alion aim for software to help keep pilots oriented

By Patrick Marshall

Mar 09, 2009

The National Space Biomedical Research Institute (NSBRI) commissioned a project to study — and develop countermeasures for — astronauts’ spatial disorientation during space flight. Alion Science and Technology, which has developed models of human response at different accelerations for the Air Force, will conduct the study under a $1.73 million grant from NSBRI.

Scientists have long known that human beings determine their physical position in the world by using a variety of cues. One of the most important pieces of data is the bending of cilia in the inner ear as they are pushed by the movement of fluids. Although that system works pretty well for Earth-bound people, it throws a few curves at pilots and astronauts.

According to one recent study, spatial disorientation was a factor in more than 20 percent of all Air Force aircraft incidents that resulted in death, permanent disability, the destruction of an aircraft or property damage exceeding $1 million. Between October 1993 and September 2002, there were 25 high-performance fighter incidents in which spatial disorientation was a causal factor, and those incidents caused 19 fatalities and more than $455 million in damage.

The problem is that although computers adequately measure changes in an aircraft’s attitude, position and acceleration, there are no reliable sensors available for detecting a pilot’s perception of those attributes. And even turning to remotely controlled aircraft does not solve the problem of spatial disorientation because studies have found that operators of remotely guided aircraft are susceptible to effects of spatial disorientation similar to those experienced in a craft.

Alion’s strategy combines knowledge about human physiology with data about an aircraft’s movement and then uses software to predict in real time the disorienting effects that are likely to afflict pilots.

Of course, it’s not enough to simply know that a pilot might be experiencing disorientation. So Alion will work to develop appropriate means of notifying pilots and delivering corrective information.

“Half of the battle is detecting when[an astronaut] is suffering from spatial disorientation, and the other is how to deal with it,” said Ron Small, Alion’s principal investigator on the project. “Zero gravity in space adds to the confusion with astronauts’ visual cues, senses and perceived orientation. By developing countermeasures, we can help the spacecraft to be controlled properly, which not only can ensure the mission is effective but help keep the astronauts safe.”

Alion already has set up simulators in its work for pilots who navigate within Earth’s atmosphere.

Through these tests, researchers have found that multiple types of notifications and levels of corrective information could be called for, depending on the situation a pilot might be facing and the demands on his or her attention. For example, if an aircraft is about to stall at low altitude, multiple visual and auditory alerts could be issued. If the aircraft is at a higher altitude and in no immediate danger, more subtle alerts could be warranted.

“When our confidence is low or if the risk to the vehicle and crew is low, we do nothing,” Small said. “If the pilot recovers or our confidence is low, we do nothing. But, as our confidence in our assessment of [spatial disorientation] increases, we trigger progressively more intrusive countermeasures. We start with visual cues that help the pilot recover to straight and level flight.… Next we use audio cues to inform the pilot that [spatial disorientation] is suspected and how to recover.”

Small said Alion also has experimented with a tactile vest, developed by the Dutch and the U.S. Navy, to see if it would help break through to the pilot’s active attention and assist with recovery.

Alion’s grant runs through August 2011, and the company intends by then to test the system in a lunar lander simulator.